In recent years, in various vehicles such as an automobile, a head-up display (hereinafter, referred to as an “HUD”) has been adopted which is structured to reflect images on a combiner front fanned in a concave plate shape to display driving informations that are superimposed on each other in view of a driver.
FIG. 8 through FIG. 10B are views showing a conventional HUD with a combiner which is attached in a dashboard of a car. The combiner HUD is generally structured by incorporating a combiner 21 formed in a concave plate shape and a projection unit 22 for projecting images toward the combiner 21 in an inside of a case main body 20 whose upper face is formed with an opening part.
The combiner 21 is integrally provided with a turnable shaft 23 along its one side and is turnable between a position where the combiner 21 closes the case main body 20 and a position where the combiner 21 is stood up from the upper face of the case main body 20 through the turnable shaft 23.
A helical gear 24 is provided at one end part of the turnable shaft 23 and a worm gear 26 provided in an output shaft of a stepping motor 25 is threadedly engaged with the helical gear 24. Further, a spiral spring 27 for urging the turnable shaft 23 in a direction so that the combiner 21 closes the opening part around an axial line is provided at the other end part of the turnable shaft 23.
Since structured as described above, the combiner HUD makes the combiner 21 stand up by the stepping motor 25 to project an image from the projection unit 22 when the combiner HUD is used and, after that, the combiner 21 is accommodated inside the opening part of the case main body 20 by an urging force of the spiral spring 27. A structure of the HUD which is incorporated inside a dashboard is also disclosed, for example, in Patent Literature 1 described below.